1 #include<bits/stdc++.h>
  2 using namespace std;
  3 #define Fopen freopen("_in.txt","r",stdin); freopen("_out.txt","w",stdout);
  4 #define LL long long
  5 #define ULL unsigned LL
  6 #define fi first
  7 #define se second
  8 #define pb push_back
  9 #define lson l,m,rt<<1
 10 #define rson m+1,r,rt<<1|1
 11 #define max3(a,b,c) max(a,max(b,c))
 12 #define min3(a,b,c) min(a,min(b,c))
 13 typedef pair<int,int> pll;
 14 const int inf = 0x3f3f3f3f;
 15 const LL INF = 0x3f3f3f3f3f3f3f3f;
 16 const LL mod =  (int)1e9+7;
 17 const int N = 1e6 + 100;
 18 string s, ss;
 19 int val[N];
 20 int nx[N];
 21 int n, m;
 22 inline int id(int x, int y){
 23     return m * x + y;
 24 }
 25 int cnt[N];
 26 void get_nt(int u){
 27     nx[0] = -1;
 28     int j = 0, k = -1;
 29     while(j < m){
 30         if(k == -1 || s[id(u,j)] == s[id(u,k)]) nx[++j] = ++k;
 31         else k = nx[k];
 32     }
 33     int pos = m;
 34     while(pos != -1){
 35         cnt[m-pos]++;
 36         pos = nx[pos];
 37     }
 38 }
 39 void get_nt_(int u){
 40     nx[0] = -1;
 41     int j = 0, k = -1;
 42     while(j < n){
 43         if(k == -1 || s[id(j,u)] == s[id(k,u)]) nx[++j] = ++k;
 44         else k = nx[k];
 45     }
 46     int pos = n;
 47     while(pos != -1){
 48         cnt[n-pos]++;
 49         pos = nx[pos];
 50     }
 51 }
 52 int a[N];
 53 LL mx[N];
 54 int main(){
 55     scanf("%d%d", &n, &m);
 56     for(int i = 1; i <= n; i++){
 57         cin >> ss;
 58         s += ss;
 59     }
 60     for(int i = 0; i < n*m; i++)
 61         scanf("%d", &val[i]);
 62     int p = 1, q = 1;
 63     memset(cnt, 0, sizeof(cnt));
 64     for(int i = 0; i < n; i++)  get_nt(i);
 65     for(int i = 1; i <= m; i++){
 66         if(cnt[i] == n) {
 67             p = i;
 68             break;
 69         }
 70     }
 71     memset(cnt, 0, sizeof(cnt));
 72     for(int i = 0; i < m; i++)  get_nt_(i);
 73     for(int i = 1; i <= n; i++){
 74         if(cnt[i] == m) {
 75             q = i;
 76             break;
 77         }
 78     }
 79     /// q*p
 80     for(int i = 0; i < n; i++){
 81         int l = 0 , r = -1;
 82         for(int j = 0; j < m; j++){
 83             while(r >= l && val[id(i,a[r])] <= val[id(i,j)]) r--;
 84             a[++r] = j;
 85             while(r >= l && a[l] <= j-p) l++;
 86             mx[id(i,j)] = val[id(i,a[l])];
 87         }
 88     }
 89     LL ans = INF;
 90     for(int j = p-1; j < m; j++){
 91         int l = 0 , r = -1;
 92         for(int i = 0; i < n; i++){
 93             while(r >= l && mx[id(a[r],j)] <= mx[id(i,j)]) r--;
 94             a[++r] = i;
 95             while(r >= l && a[l] <= i-q) l++;
 96             if(i >= q-1) ans = min(ans, mx[id(a[l],j)]);
 97         }
 98     }
 99     printf("%lld\n",1ll*ans*(p+1)*(q+1));
100     return 0;
101 }